the GMC Sierra full-size pickup was restyled, inside and out, and boasted roomier cabins, greater maximum towing capacity and higher gas mileage. For 2008, XM Satellite Radio is now standard, and light-duty Sierras get a trailer brake controller that aids drivers when towing. and a new All Terrain trim level features skid plates, 18-inch chrome wheels, Rancho shocks, a chrome grille and trim, special badges and unique gauges. Heavy-duty dualie trucks now have 17-inch wheels. The Sierra comes with OnStar, with the first year of Safe & Sound service free. This plan includes automatic OnStar notification in the event of a collision, stolen vehicle tracking and remote door unlocking should you lock your keys in the car. - 2008 GMC Sierra 1500 4WD Crew Cab 143.5" SL - Power Door Locks, Tilt Wheel, Remote Keyless Entry, Cruise Control, Steering Wheel Stereo Controls, Communications-Onboard Hands Free, Tire-Pressure Monitoring System, Security System, CD Player, Audio-Satellite Radio, Tinted Glass - Deep, Additional Power Outlet(s), Air Conditioning, Seats-Front Bench-Split, Seat-Lumbar-Driver, Seat-Rear Pass-Through, Floor Mats-Front, Cloth Seats, Mirrors-Pwr Driver, Mirrors-Vanity-Passenger, Wheels-Chrome, Transmission-Overdrive-Switch, Headlights-Auto-Off, Reading Lamps-Front, Air Bag - Driver, Air Bag - Passenger, Traction Control, Power Steering, Front Disc Brakes, Brakes-ABS-4 Wheel, 4 Wheel Drive, Daytime Running Lights, Tow Hooks-Front